The present invention relates to medical instruments particularly endoscopic instruments used for procedures such as internal surgery.
Conventional endoscopic instruments for internal surgery such as scissors, graspers, ligators, forceps, dissectors, endoloops, cautery, etc., are useable with a surgical trocar. The instruments comprise an operating handle, an elongate tube for projecting the instrument through a trocar, and working components such as scissor blades fitted to the operating end of the elongate tube. The tube encases a linkage interconnecting the handle and the working components so that by manipulating the handles the instrument is employed. In operation it is usually necessary to rotate the working components with respect to the longitudinal axis of the elongate tube in order to place the instrument in proper orientation for a medical procedure. Conventional instruments include a rotary wheel attached to the elongate tube for rotating the tube and working components as necessary to achieve proper orientation. This arrangement is simple and straightforward, however the arrangement does require the operator to use both hands, i.e., the right hand manipulates the instrument handle while the left manipulates the rotary wheel to orient the instrument working components to correct angle of attack. There is need for an endoscopic instrument enabling a surgeon to use only one hand for orienting and actuating the working components of the instrument.